It must conjure up an image of you (as in your smiling face) or of your brand—and by “brand” I mean one or two simple keywords that will lead to you every time: your name, your location, your practice specialty.

If you buy a domain with an extension other than .com, be certain to investigate who owns the .com version. If it’s a person or business that could be confused with you, don’t buy. If there’s a published website offering the same or similar services as you, you need to find new keywords and the .com to go with them. Otherwise, you’re already starting in a hole SEO-wise. The established site will likely always rank higher than you because it has been live longer using them. (Sometimes the SEO stuff is just plain old common sense.) I’m no lawyer, but when I worked in the litigation department of a trademark/patent firm, the words “confusingly similar” were the ones that I recall never wanting to hear.

Word to the wise; the "confusingly similar" language the author refers to has to do with potential liability for trademark infringement if your domain either bears a visual similarity to a distinctive or famous mark (i.e. you might be cybersquatting under Section 1125(d) of the Lanham Act) or if it causes consumer confusion because the public might mistakenly believe your website is affiliated with the owner of a registered mark under Section 1125(a). You want to make sure you avoid both of those situations when you're selecting a domain name.